Spinning of textile yarns

ABSTRACT

A method and apparatus for fibrillating a plastic film and then spinning the fibrillated fibers into a yarn by the open-end spinning method.

DCC. 7, 1971 J, M SHEPHERD I'AL 3,624,996

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SPINNING OF TEXTILE YARNS Filed Aug. 8, 1969 2 Shoots-Shed 2 mM/M United States Patent O U.S. Cl. 57-58.91 2 Claims ABSTRACT OF THE DISCLOSURE A method and apparatus for fibrillating a plastic film and then spinning the fibrillated fibers into a yarn by the open-end spinning method.

The present invention relates to the spinning of textile yarns and is particularly concerned with a method of and apparatus for the open-end spinning of textile yarns directly from a film of synthetic plastics material in sheet or strip form.

In the open-end spinning of textile yarns, a twisted yarn may be formed by continuously depositing discrete fibres on a rotating collecting surface, continuously removing them from the surface to form the tail-end of a yarn and drawing off the continuously formed twisted yarn. It has hitherto been proposed to supply the fibres assembled in the form of a roving or sliver, which is continuously advanced to a fibre separating station where the fibres are separated from the rovin-g and carried in an airstream to the fibre collecting surface.

According to a first aspect of the present invention there is provided a method of open-end spinning of textile yarns comprising the steps of continuously advancing a sheet or strip of film of a synthetic plastics material to a fibre forming station where the film is converted into fibres of staple length and conveying said fibres from the fibreforming station to an open-end spinning device where they are spun into a yarn.

According to a second aspect of the present invention, there is provided apparatus for the open-end spinning of textile yarns comprising means for advancing a sheet or strip of lfilm of a synthetic plastics material to a fibrillating station, brillating means for fibrillating the fihn at said station into fibres of staple length, an open-end spinning device and means for conveying the fibres to said openend spinning device to form a spun yarn.

According to a preferred embodiment of the present invention, the fibrillating means comprises stretching means to stretch the sheet or strip of film until it fibrillates into staple fibres.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic sectional side elevation of apparatus according to a first embodiment of the invention,

.FIG. 2 illustrates a film subjected to a slitting operation by the apparatus shown in FIG. l.

FIG. 3 is a diagrammatic sectional side elevation of apparatus according to a second embodiment of the invention, and

FIG. 4 is a schematic rear elevation of part of the apparatus illustrated in FIGS. l and 3.

Referring first to FIG. 1, a Film F, in the form of a continuous strip, is supplied by a roll 11 and advanced through a series of rollers 12, 13, 14 and 15 which serve to flatten and straighten it. A heating element may, if desired, be employed in this Zone to assist in the straightening of the film but preferably this is done by heating the rollers '12 to 15. The film is advanced by rollers 16 and 17 which guide and locate the `film on a slitting roller 18. The slitting roller 18 is provided with slitting pins 19, has a circumferential speed differing from that of the -film F and produces a slit film 'F1 which may be in the form shown in FIG. 2 with slits 20 or in other forms depending on film and slitting roller speeds and also pin geometry. The slit film F1 then passes through two pairs of rollers 21, 22 and 23, 24 constituting a stretch-break zone, the surface speed of the rollers 23, 24 'being sufficiently greater than that of the rollers 21, 22 as to cause the slit film F1 to fibrillate into staple fibres F11. The slit film F1, as illustrated in FIG. '2, is weakest at the ends of the slits 20 and will fail at these points when stressed by passing through the stretch-break zone. The fibres F11 are delivered by a further pair of rollers 25, 26 which present the fibres F11 in discrete form to a feed tube 27 which conveys them to an open-end spinning device 28.

Separation of the fibres F11 from each other may be facilitated by inserting a rotating beater to Contact the film between rollers 21, 22 and 23, 24 or between the rollers 23, 24 and 25, 26. Alternatively, or in addition, there may be provided, as illustrated in FIG. 3, a high speed rotary beater 29 covered with saw tooth wire 30 or pins to act on the fibrillated film emerging from rollers 2'5, 26 to further separate the fibres and assist in conveying them to the spinning device 28.

The open-end spinning device 28 shown in FIGS. l and 3 comprises a spinning rotor 31 having an internal collecting surface although other open-end spinning devices may, if desired, be employed. The rotor is contained in a housing 3'2 and is preferably partially closed by a cover plate `33 of the housing. Air is removed from the interior of the rotor either by means of the rotor itself, or by external suction means communicating with a suction duct 34. Fibres are removed from the fibre collecting surface of the rotor 31 and twisted into an end of yarn Y in the well known manner in open-end spinning machines and the twisted yarn Y is continuously removed from the spinning rotor 31 through a delivery duct 35 by a pair of takeup rollers 36, 37.

A plurality of units of the form shown in FIG. 1 or 3 may be supplied from a single roll 11 of film or from film from a single extruder, the film F being divided longitudinally throughout its length into a plurality of sheets or strips by a dividing roller 38 shown in detail in FIG. 4 and including circular cutting blades 39 arranged with equal spacing along the roller 38.

It will be obvious that other methods can be used to initiate or cause fibrillation in sheets or strips of film of synthetic plastic materials instead of the particular arrangement hereinbefore specifically described and illustrated. The invention is of particular use in the processing of films of synthetic polymeric material, for example, polypropylene or polyolefin films, into spun textile yarns.

What we claim as our invention and desire to secure by Letters Patent is:

1. A method of open-end spinning of textile yarns comprising the steps of continuously advancing a sheet or strip of film of a synthetic plastics material to a fiber forming station where the film is converted into discrete fibers of staple length and conveying said fibers in discrete manner from the fiber forming station to an open-end spinning device where they are spun into a yarn.

2. A method according to claim 1, including the step of stretching the sheet or strip of film at the fibre-forming station to cause the film to fibrillate into said fibres of staple length.

3. A method according to claim 2, wherein the film is in sheet form and is provided with an array of discontinuous longitudinal slits therein, whereby subsequent stretching of the film at the fiber-forming station causes the film to break at the ends of the slits to produce said discrete fibers of staple length.

4. A method according to claim 1, wherein the fibres produced in the fibre-forming station are subjected to opening by fibre-opening means in their passage to said open-end spinning device.

5. A method according to claim 1 wherein the sheet or strip of film advanced to the fibre-forming station is one of a plurality of portions of a wide sheet of lm continuously and longitudinally divided throughout its length.

6. Apparatus for the open-end spinning of textile yarns, comprising means for advancing a sheet or strip of lfilm of a synthetic plastics material to a fibrillating station, brillating means for fibrillating the film at said station into discrete fibers of staple length, an open-end spinning device, and means for conveying said fibers in discrete manner to said open-end spinning device to form a spun yarn.

7. Apparatus according to claim 6, wherein the said fibrillating means comprises stretching means to stretch the sheet or strip of film until it iibrillates into discrete fibres.

8. Apparatus according to claim 7 wherein the film is in sheet form and the apparatus comprises slitting means to produce in the sheet of film to be fed to the stretching means an array of discontinuous longitudinal slits therein.

9. Apparatus according to claim 8, wherein said slitting means comprises a slitting roller provided with slitting pins and arranged in operation to have a peripheral speed differing from that of the film thereby to produce in the sheet of film advanced in contact therewith said array of discontinuous longitudinal slits.

10. Apparatus according to claim 7, comprising fibreseparating means to act on the film when being subjected to stretching by said stretching means. v i v 11. Apparatus according to claim 6 wherein said fibrillating means includes fiber-opening means to act on the fibrillated film to separate the fibers and assist in their conveyance to the said spinning device.

12. Apparatus according to claim 6, comprising film supply means for supplying film continuouslyv to said fibrillating station and one or more other fibrillating stations, said supply means including means for dividing the lm from the supply longitudinally and continuously throughout its length and for feeding the divided portions of the film to the fibrillating stations.

References Cited UNITED STATES PATENTS 2,853,847 9/1958 Keeler et al. 57-58.89 X 3,273,329 9/1966 Scragg 57-167 X 3,273,771 9/1966 Beaumont 57-1 67 UX 3,434,184 3/ 1969 Doudlebsky et al.

57-58.91 UX 3,470,595 10/ 1969 Goppel 28-72 3,474,611 10/1969 Suzuk et al 28-1 3,494,118 2/1970 Bobkowicz et al. 57--58.91 X 3,500,626 3/ 1970 Sandiford 28--72 X 3,506,535 4/ 1970 Prevorsek et al 28-1 X 3,511,044 5/1970 Stary 57-58.91

DONALD E. WATKINS, Primary Examiner U.S. Cl. X.R. 57-15 6 

